6L80E/6L90E TRANSMISSION
In 2006, General Motors introduced its new line of innovative 6L80E transmissions. Unlike previous GM transmissions which evolved from earlier transmission models, GM's objective with the 6L80E was to design a new line of transmissions from scratch. The 6L80E would usher in a new meaning to electronically controlled hydraulic transmissions, becoming a popular choice for high-performance cars, heavy-duty trucks and SUVs.
The implementation of the SuperMatic 6L80E concentrated on having a new transmission to replace the 4L60E/4L80E transmissions. These transmissions were upgraded and re-engineered transmissions from earlier models; the 4L60E was based on the earlier 700R4 and the 4L80E had its roots in the TH400. Rather than continuing down the path of upgrading older design transmissions to meet modern standards, the General Motors Hydra-Matic division embarked on a new project to develop an entirely new family of transmissions. The 6L80E was the first transmission to be introduced under this new platform.
Many vehicles have come with the 6L80 (GM code MYC) since its inception, including the Chevy Silverado/GMC Sierra 1500, third-generation Cadillac Escalade, C6 Chevy Corvette, Hummer H2, Chevy Tahoe, GMC Yukon and fifth-gen Chevy Camaro. Here's a deeper look at how GM made the 6L80 a modern 21st-century automatic transmission popular for on-road and off-road vehicles.
Design Concept
The 6L80E was purposely engineered around a modular design concept. The bell housing and rear tail housing sections are detachable from the main transmission body. This modular design of the 6L80E allows for variations to accommodate different engines and vehicle applications such as the 6-liter Vortec or 6.6L gas Chevy engine.
The 6L80E is based on three gear assemblies. The three gear set assemblies comprise of an input planetary gear set and two output gear sets. The first compound gear set contains three pairs of pinion gears on the output carrier. The second assembly meshes with the sun gear, while the third compound gear set meshes with the ring gear. The combined gear sets provide the six forward gear ratios and reverse.
Transmission Control Module
Shifting of the transmission is fully automatic and is accomplished using the 32-bit Transmission Control Module (TCM) inside the transmission. The TCM collects and monitors various electronic sensor inputs. It then uses this information to enable the transmission to shift at optimal sequences. The TCM dictates the variable bleed pressure control solenoids to command shift quality and timing. The TCM controls the lock and release of the torque converter clutch. This delivers supreme fuel efficiency without sacrificing vehicle performance. The TCM monitors the transmission's performance, compensating for component wear and adjusting accordingly so performance is consistent for the life of the transmission.
Performance Algorithm Shifting/Braking
Performance Algorithm Shifting (PAS) is available for some applications. This system monitors how assertively the driver is using engine output to determine at what engine speed to upshift or downshift. The PAS can determine if the vehicle is being driven aggressively. If the algorithm recognizes this condition, it can initiate downshifts and actuate lower gears for ideal vehicle performance. The PAS can also detect a drop in engine power during an upshift shift. In the chance of possible clutch damage, the PAS will auto-correct the shift strategy and stabilize the shift sequence. Some truck applications also offer a Tow/Haul mode. When activated, grade braking and clutch line pressure are initiated.
Driver Shift Control
The Driver Shift Control (DSC) is an additional shift option that allows the driver to shift the transmission manually. When the DSC shift selector lever is actuated, the driver may manually select upshifts or downshifts like a manual transmission. Electronic safeguards are present to prevent the driver from over-reviving or accidentally shifting.
6L80E vs. 6L90E
Within one year of GM introducing the 6L80E, the 6L90E hit the market. This version is 1.375 inches longer than the 6L80E and shares 75% of the internal components. The engine torque rating was also slightly increased, but the output torque rating jumped up by nearly 220 lb.-ft. to 885 lb.-ft., GM also raised the GVW of 15,000 ls. and GCVW of 21,000 lb., and the spline counts changed from 32 to 29.
The 6L90E is intended as a heavy-duty version of the 6L80E. Upgrades include a strengthened input gear set and a strengthened wider output gear set. The 6L90E (GM code MYD) also contains one more clutch plate in each clutch pack than the 6L80 for extreme applications. It was the stock transmission on vehicles such as the Chevy Silverado 2500/3500HD, fifth-gen Chevy Camaro ZL1, second-gen Cadillac CTS-V and Chevy Suburban 2500. It's still the OEM transmission for the Chevy Express 2500/3500 and GMC Savana 2500/3500 full-size vans.
6L80E Transmission Conversion
The 6L80E and 6L90 are prime candidates for conversions in a multitude of vehicle applications. The length of the transmission is remarkably short for a six-speed transmission. Still, the wheelbase length of some vehicles can limit some conversion applications. We do not recommend using this transmission on CJ5 Jeeps and other similar short-wheelbase vehicles. On longer-wheelbase vehicles, this transmission is well-suited. The transmission has a narrow oil pan for better front driveshaft clearance. The 6L80E also has self-contained electronic sensors which allows for easy adaptation. Most of our adapter kits utilize the existing 4WD output shaft, so dismantling the transmission is typically not required.
Although many 6L80E transmissions share the common 90-degree bolt as older Chevy V8 engines, special consideration should be used when selecting an. The 6L80E is found behind Gen IV and Gen V engines that share advanced computer controls. At this time, we only recommend using computer-controlled engines that are compatible with the 6L80E.
Enter "6L80" or "6L90" into the search bar on the main Advance Adapters website to find adapters for linking these transmissions to many different engines and transfer cases. We have solutions to install a 6L80 transmission in the Ford Bronco, Toyota 4Runner, Jeep Grand Wagoneer, International Scout 800 and many other vehicles past and present. See the full specifications below or contact Advance Adapters to talk to an expert about your transmission conversion needs.
6L80E Specifications:
Case with Bell Housing Length: 23.5 inches
Adapter Length: 3.75 inches
Case Material: Aluminum
Output Shaft Spline: 32
1st Gear Ratio: 4.02
2nd Gear Ratio: 2.36
3rd Gear Ratio: 1.53
4th Gear Ratio: 1.15
5th Gear Ratio: 0.085
6th Gear Ratio: 0.667
Reverse: 3.06
Transmission Weight: 200-230 lb.
Fluid Type: Dextron VI
6L90E Specifications*:
Case with Bell Housing Length: 25 inches
Adapter Length: 3.75 inches
Output Shaft Spline: 29
*Note: Except for the items noted, 6L90E specs are identical to the 6L80E.